Blower Motor Does Not Operate

Blower Motor Does Not Operate

Circuit Diagram





Normal operation of blower motor
Blower motor speed is controlled by the blower switch at the center of the dash panel and by a resistor assembly in the blower unit.

When the blower switch is in the OFF position, the motor ground circuit is open and the blower motor does not operate. When the switch is in the first (Low) position, current flow from the blower motor is restricted by the three resistors (vehicles without A/C: four resistors) in the resistor assembly, and the blower motor turns at low speed.

Changing the blower switch to the second (Mid), third (High), or fourth (Super-high) causes the circuit resistance to decrease, and the blower motor speed becomes correspondingly faster.


Step 1







1. Check the fuses.
2. If a fuse is burned, check for a short circuit in the wiring harness before replacing the fuse.
3. If the fuses are OK, go to Step 2.

Step 2
1. Turn the ignition switch ON.








2. Measure the voltage at the following terminals of the blower motor relay connector.

Step 3
1. Turn the ignition switch ON.
2. Turn the blower switch to the fourth position.








3. Measure the voltage at terminal-wire (L/O) of the blower motor connector.

Step 4
1. Turn the ignition switch ON.
2. Turn the blower switch and A/C switch OFF.








3. Measure the voltage at the terminal-wires of the resistor assembly.

Step 5
1. Turn the ignition switch ON.
2. Turn the blower switch to the fourth position.








3. Measure the voltage at terminal-wire (B) of the blower switch connector.

Step 6
1. Turn the ignition switch ON.
2. Turn the blower switch and A/C switch OFF.








3. Measure the voltage at the terminal-wires of the blower switch connector.